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Ci)FIRIGHT DEPOSm 



An Ice Cream 
Laboratory Guide 



BY 

W. W. FISK 

Assistant Professor of Dairy Industry at 
Cornell University 

and 

H. B. ELLENBERGER 

Instructor of Dairy' Industry at Cornell University 



NEW YORK 

ORANGE JUDD COMPANY 

1917 



-^^1 

f*^ 



Copyright, 1917, by 
ORANGE JUDD COMPANY 

All Rights Reserved 



SEP 26 1917 

If DMd 

Printed in U. S. A. 



©C1.A476258 



TABLE OF CONTENTS 

PAGE 

Preface ..... i 

Discussion of Laboratory Equipment 3 

Exercise I 
Inspection and Study of Ice Cream Machinery .... 6 

Discussion of Standardization 8 

Exercise II 
Standardization 12 

Exercise III 
Testing Ice Cream for Fat 14 

Exercise IV 
Effect of the Salt and Ice Mixture on Temperature . . 16 

Classification of Ice Cream 18 

The Use of Stabilizers 21 

Exercise V 
Freezing Plain Ice Creams 24 

Exercise VI 
Methods of Measuring Swell 26 

Hardening Ice Cream 28 

Exercise VII 
Freezing Fruit Ice Cream. Hardening in Salt and Ice . 30 

Exercise VIII 
Freezing Nut Ice Cream 32 

Exercise IX 
Freezing Bisque Ice Cream 34 

Exercise X 
Making Bricks and Fancy Moulded Ice Creams » • . Z7 

Exercise XI 
Freezing Custard Ice Cream 41 

Exercise XII 
Freezing Parfait or French Ice Creams 45 

Exercise XIII 
Freezing Puddings 49 

Exercise XIV 
Freezing Ices . 52 

ill 



CONTENTS 

PAGE 

Exercise XV 
Freezing Water Sherbets 54 

Exercise XVI 
Freezing Milk Sherbets 56 

Exercise XVII 
Freezing Punches and Lacto 58 

Exercise XVIII 
Freezing Mousse 60 

Exercise XIX 
Standardize Mix to a Given Percentage of Fat .... 62 

Score Card for Judging Ice Cream , . 64 

Exercise XX 
Judging Plain Ice Creams 66 

Exercise XXI 
The Effect of Fat Content on Ice Cream 68 

Exercise XXII 
The Effect of Different Binders on Ice Cream .... 70 

Exercise XXIII 
The Effect of Varying Percentages of Milk Solids Not 

Fat on Ice Cream "jo. 

Exercise XXIV 
Freezing Ice Cream from Raw, Pasteurized, Emulsified 

and Homogenized Cream 74 

Exercise XXV 
The Effect of Aging Cream on the Viscosity and Swell . 76 

Exercise XXVI 
The Effect of the Temperature of the Mix as It Enters the 

Freezer on the Swell 78 

Exercise XXVII 
Effect of the Time of Freezing on the Swell and Quality 

of the Ice Cream 80 

Exercise XXVIII 
Bacterial Counts of Ice Cream 82 

Exercise XXIX 
Testing Samples of Gelatin 84 

Exercise XXX 
Trip to Commercial Plants 86 

Exercise XXXI 
Students' Receipts 88 



PREFACE 

The manufacture of ice cream is based on certain 
scientific principles. It is the purpose of this labora- 
tory manual to help the student to better understand 
the application of these principles. This manual, 
which is the result of several years' experience in 
teaching, is not intended as a textbook, but as a brief 
and concise outline of laboratory exercises. It will 
also serve as a suitable place for the student to record 
observations. The exercises have been prepared, so 
that each instructor may make selections and combina- 
tions suitable for the equipment and the needs of his 
course. 

Because this is comparatively a new subject and the 
ideas regarding ice cream production and manufacture 
are constantly changing, the authors recognize that this 
manual will need frequent revisions. An effort will 
be made to keep it thoroughly up to date. 

Dairy Laboratories, 

Ncit York State College of Agriculture, 

at Cornell University, 

Ithaca, New York, 

February, J917. 



An Ice Cream Laboratory Guide 



LABORATORY EQUIPMENT 

The exercises in this manual may be selected or 
easily modified, so that they will be suitable for any 
laboratory equipment. For example, the receipts have 
been prepared with the expectation that a 10-gallon 
freezer would be used ; if a smaller freezer is used, the 
receipts may be reduced proportionally. 

Much better instruction can be given if the equip- 
ment includes an artificial refrigerating plant for freez- 
ing and hardening the ice cream. If the equipment 
does not include an artificial refrigerating plant, a tub 
and can freezer, using an ice and salt mixture for 
freezing, and a wooden box for packing and hardening 
the ice cream, in ice and salt, may be used. The 
hardening box should be made of 2 inch matched 
lumber so that it will not leak. The size of the box 
will be determined by the amount of ice cream manu- 
factured. It should be built in compartments which 
will hold six five gallon cans. This will require a box 
26 inches wide by 32 inches deep by 36 inches long, 
outside measurement, with a hinged cover for each 
compartment. 

If much ice cream is to be made an ice cream mixer 
is a necessity, but if a small amount is made each batch 
may be mixed in a 40 quart milk can. A homogenizer 
and emulsor may be included in the equipment. 

With whatever type of freezer is used, there should 
be one or two small hand freezers, to freeze small 

3 



4 AN ICE CREAM LABORATORY GUIDE 

batches and to try new receipts. An ice crusher should 
be included for crushing ice. 

The equipment should include the necessary small 
utensils, such as pails, dippers, ladles, spoons, ther- 
mometers, scales, measures, pack cans, etc. 

There should be a suitable sink connected with hot 
and cold water and steam, for washing and scalding 
the utensils. A suitable rack should be provided for 
drying and holding the utensils and pack cans. Be- 
cause of the salt used, care must be exercised, as it is 
liable to get on the utensils and cause them to rust. 

All belts and gears on machines should be protected, 
so that persons cannot be caught and injured in them. 



AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER I 

INSPECTION AND STUDY OF ICE CREAM 
MACHINERY 

Artificial refrigerating systems. 

I. State briefly the principles involved in an arti- 
ficial refrigerating plant. 

11. Make drawings showing the working principles 
of the refrigerating system. 

III. Tell how to start and stop the compressor. 
Ice cream freezers. 

I. Tell the principles on which the various types 
of freezers work. 

II. How can the temperature in the different types 
of freezers be regulated? 
Cleaning utensils. 

I. How should utensils be washed? Why? 
II. Are all utensils so constructed that they may be 
easily and thoroughly cleaned? What provisions 
have been made to make cleaning easy ? 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE I REPORT 



AN ICE CREAM LABORATORY GUIDE 



STANDARDIZATION 

One of the main requirements for a successful ice 
cream business is uniformity of quality. In order to 
obtain this, it is necessary to have cream each time 
containing the same percentage of fat. As it is im- 
possible to always get cream of a uniform fat content, 
the cream must be standardized. That is, the percent- 
age of fat must be either increased or decreased to the 
desired amount. It is the usual practice to have richer 
cream than is to be used and reduce it by the addition 
of less rich cream, whole milk, or skim milk. If the 
cream was lower in percentage of fat than was desired, 
it could be standardized only by the addition of richer 
cream. 

Prof. R. A. Pearson has devised a very simple 
method, known as the rectangular method of standard- 
ization. This method is as follows : draw a rectangle 
and place in the center the percentage of fat desired. 
At the left hand corners place the percentages of fat 
in the materials to be mixed. It is customary to place 
the larger figure at the top, thus: 




16 parts of] 
25% cream] 



5 parts of 
milk 



= 21 parts 
"of 20% 
cream 



Then subtract diagonally, placing the remainders 
at the right hand corners, as shown above. These 



AN ICE CREAM LABORATORY GUIDE Q 

show the proportions by weight in which the materials 
must be mixed to give the desired percentage of fat. 

A problem may serve to illustrate the method. 

How many pounds each of 30% cream and 4% 
milk are necessary to make 260 lbs. of 20% cream? 




This shows 16 lbs. 30% cream and 10 lbs. 4% milk 
make 26 lbs. of 20% cream, but 260 lbs. is required. 
This is best solved by simple proportion: 

10 lbs. milk : 26 lbs. 20% cream : : x lbs. milk : 260 
lbs. 20% cream. 

Solving X = 100 lbs. 4% milk required and 260 lbs. 
— 100 lbs. milk = 160 lbs. 30% cream required which 
may also be determined by proportion. 

To be sure no mistakes are made in figuring, it is 
best to prove all standardizations. The proof is 
simple. • 

260 lbs. 20% cream contains 52 lbs. fat (required). 

160 lbs. 30% " " 48 lbs. " 

100 lbs. 4% milk " 4 lbs. " 

Making a total of 52 lbs. fat, the amount 
required. 
In the above problem a definite amount of the mix- 
ture was required. There is another class of standard- 
ization problems in which the amount of one of the 



lO 



AN ICE CREAM LABORATORY GUIDE 



materials is given, to find the quantity of the other re- 
quired to standardize it: 

How much 4% milk must be mixed with 420 lbs. of 
40% cream to make a mixture testing 25% fat? 




This shows that 15 lbs. of 4% milk will standardize 
21 lbs. of 40% cream to a cream tasting 25% fat. But 
there are 420 lbs. of 40% cream to standardize. By 
simple proportion, 

15 lbs. 4% milk : 21 lbs. 40% cream :: x lbs. 4% 
milk : 420 lbs. 40% cream. 
Solving X r= 300 lbs. 4% milk 
420 lbs. cream + 300 lbs. milk = 720 lbs. 25% 
cream. 
Proof : 

720 lbs. of 25% cream contains 180 lbs. fat. 
300 lbs. of 4% milk " 12 lbs. " 

420 lbs. of 40% cream '' 168 lbs. " 



Making a total of 180 lbs. fat. 



12 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER II 
STANDARDIZATION 

Cream and milk to standardize will be furnished. 

Test both by the Babcock method and report the 
result to the instructor, who will assign a definite per- 
centage of fat for the standardized mixture. 

After standardizing, test a sample of the standard- 
ized mixture by the Babcock method to test the ac- 
curacy of your work. 

Report all calculations and results on opposite page. 



AN ICE CREAM LABORATORY GUIDE 1 3 

EXERCISE II REPORT 



14 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER III 
TESTING ICE CREAM FOR FAT 

Ice cream cannot be tested for fat, by the Babcock 
test, as milk, because the acid chars the sugar, which 
interferes with the reading. Various methods of test- 
ing ice cream, so as to overcome this disadvantage have 
been devised. A few of the simpler ones follow. 

Test a sample of ice cream by each of the following 
methods and report results on the opposite page. 

Method of Prof. H. E. Ross: Mix equal parts by 
weight of melted ice cream and water. Weigh into a 

9 gram 50% cream bottle 9 grams of the mixture. 
Add 17.5 cc. of glacial acetic acid. Shake for two to 
three minutes. Next add 15 cc. of sulphuric acid 
such as is used for the Babcock test. Shake for one 
minute and proceed as in the ordinary Babcock test. 
Multiply the reading by two. 

Method of J. P. Dawson: Weigh 18 grams of 
melted ice cream at a temperature of 70 degrees F. 
into a 30%, 9 inch cream test bottle. Add 8 cc. of 
glacial acetic acid, agitate gently for 2 minutes and add 

10 cc. of Babcock sulphuric acid. Shake and centri- 
fuge in the usual manner. 

Note : There appears to be no reason why one half 
the quantities of ice cream and acids may not be used 
in a 6 inch 9 gram 50% cream bottle. 

Method often used by the authors : Weigh 9 grams 
of melted ice cream into a 6 inch 50%, 9 gram cream 
bottle and add about 9 cc. of water. Add three 
quarters of an acid measure of glacial acetic acid and 
mix thoroughly. Next add two thirds of an acid 
measure of Babcock sulphuric acid. Shake till well 
mixed and centrifuge in the usual manner. 



AN ICE CREAM LABORATORY GUIDE 1 5 

EXERCISE III REPORT 



It) AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER IV 

EFFECT OF THE SALT AND ICE MIXTURE 
ON TEMPERATURE 

Alake a brine one part salt to ten parts of water by- 
weight. With part of this fill the can of a hand 
freezer two thirds full just as though it were an ice 
cream mix which you were going to freeze. Record 
the temperature of this brine. 

Trial 1. Using a mixture of one pound of salt to 
10 lbs. of crushed ice, try freezing the brine in the 
freezer can. Turn 10 minutes, keeping the freezer 
can well covered with the ice and salt mixture. Open 
and record the temperature of the brine in the can. 

Trial 2. Empty the freezer can and tub and refill 
the can with more of the brine used in Trial 1. Be 
sure to have it the same temperature. Using a salt and 
ice mixture of the same proportions, pack the tub again 
and in addition add enough cold water so that it starts 
to run from the overflow hole in the tub. Turn the 
freezer 10 minutes, recording the temperature of the 
brine flowing from the overflow hole every 2 minutes. 
Be sure to keep the ice-salt-water mixture in the tub 
well mixed by punching with a stick such as a sawed- 
ofif broom handle. Again record the temperature of 
the brine in the can. Why does it differ from what it 
was in Trial 1 ? 

Trial 3. Repeat Trial 2, except use a mixture of 
salt and ice one to six instead of one to 10. Record 
results. 

Trial 4. Repeat Trial 3 but do not mix the ice, salt. 



AN ICE CREAM LABORATORY GUIDE I7 

and water in the tub. Explain the difference in the 
results obtained in Trials 3 and 4. 

Tabulate and report all the data which you have 
recorded. 



EXERCISE IV REPORT 



l8 AN ICE CREAM LABORATORY GUIDE 



CLASSIFICATION OF ICE CREAM 

In the absence of the adoption of any uniform 
standard classification of ice cream, the following 
classification in use by the authors is given. It is 
simple, yet comprehensive, and is arranged according 
to fundamental differences in composition. This 
seems to be the most logical basis for classifying ice 
cream and is very satisfactory from a laboratory 
standpoint. Exercises and representative formulas 
will be given for each of these classes. 

I. Plain or uncooked ice cream, often known as 
Philadelphia ice cream, is made from cream, sugar, 
and flavoring, with or without condensed milk or some 
stabilizer. It may be subdivided as follows : 

1. Plain — Flavors such as Vanilla, Chocolate, Car- 

amel, Coffee, Mint, etc. 

2. Fruit — Flavored with fresh or canned fruits 

such as Peach, Pineapple, Strawberry, Cherry, 
etc. 

3. Nut — Flavored with such nuts as Walnut, Al- 

mond, Filbert, Chestnut, Pistachio, etc. 

4. Bisque — Flavored with Marshmallows, Maca- 

roons, Sponge Cake, Nabisco Wafers, Grape- 
nuts, etc. 
II. Cooked ice cream, often known as French or 
Neapolitan ice cream, is made from cream, sugar, 
flavoring, and eggs. As custards they sometimes con- 
tain flour or cornstarch. The following subdivisions 
are recognized: 

1. Parfaits or French — Flavors such as Vanilla, 
Chocolate, etc., are most common, but various 
fruits are sometimes used. 



AN ICE CREAM LABORATORY GUIDE 1 9 

2. Puddings — These are highly flavored with va- 

rious dried and candied fruits, nuts, and spices. 
Examples are Nesselrode, Roman, and Eng- 
lish Plum. 

3. Custards — These contain flour, cornstarch, tapi- 

oca, or other similar ingredients, and are al- 
most always flavored with vanilla. 

III. Sherbets and Ices are made from water or 
milk, sugar, often egg albumen and a stabilizer, and 
flavored with fruit juices or other natural flavoring. 
The most prominent classes are the following : 

1. Ices — Made from water, sugar and some natural 

flavoring without eggs or a stabilizer. This 
may include granites and frappes. Granites 
are frozen with little agitation, while frappes 
are only semi- frozen to a slushy consistency. 

2. Water Sherbets — are made the same as ices with 

the addition of egg whites and sometimes a 
stabilizer. If the whole egg is used, they are 
sometimes called souffles. 

3. Punches — are ices or water sherbets flavored 

with liquors or highly flavored with fruit 
juices and spices. 

4. Milk Sherbets — Made from skimmed or whole 

milk, sugar, and egg whites, with or without 
a stabilizer and flavored with some natural 
flavoring. 

5. Lacto — Made from skimmed or whole sour milk 

instead of sweet milk but in other respects 
they resemble milk sherbets. 

IV. Mousse is a rich cream, sweetened and whipped 
to a stifif froth, flavored and frozen in moulds or cans. 

In the laboratories at the New York state argricul- 
tural college 20% cream is used in making all plain or 
uncooked ice creams. Therefore in the following ex- 



20 AN ICE CREAM LABORATORY GUIDE 

ercises and formulas a 20% cream is used as a base in 
most cases. This, however, may be reduced to 18% 
or 16% if it is thought desirable. 

It must be remembered that the formulas given are 
for laboratory use and are not especially recommended 
as ideal formulas for commercial use. Many of them 
have given good results in commercial plants but there 
are so many variations and combinations possible that 
no single formula or group of formulas can be given 
as ideal for all commercial plants. 

If the use of condensed milk is desired eight pounds 
of whole condensed milk may be substituted for the 
same amount of cream with excellent results in any 
of the formulas given for plain ice cream. Most com- 
mercial plants use condensed milk to give the ice cream 
more body and better standing quality. 



AN ICE CREAM LABORATORY GUIDE 21 



THE USE OF STABILIZERS 

A stabilizer of some kind is generally admitted to 
be necessary in commercial ice cream. The three most 
commonly used are gelatin, ice cream powders and 
gum tragacanth. 

Gelatin may be prepared in any of the three follow- 
ing ways, using either milk or water for dissolving it. 
However, if milk is used, one of the first two methods 
should be used, so as to avoid any cooked flavor from 
boiled milk. 

1. Using one pint to one quart of water or milk to 
each two ounces of gelatin, soak the gelatin in the cold 
liquid for fifteen to thirty minutes. Then heat the 
mixture up to a temperature of 160 degrees to 170 de- 
grees F. and add to the cream with rapid agitation. 

2. The same as number one, except heat the mix- 
ture only to a temperature of 125 degrees to 130 de- 
grees F. for a sufficient time to thoroughly dissolve all 
of the gelatin. 

3. Heat the necessary amount of water to boiling, 
dump the gelatin into it and stir till dissolved. Then 
add to the cream with rapid stirring. 

Ice cream powders should be used according to the 
directions given with them. 

Gum tragacanth stock is made in the following 
manner. Place the dry gum in cold water, using one 
ounce of gum to four pounds of water. Heat slowly 
and uniformly over a low flame or better in a double 
boiler to a temperature of about 110 degrees F. Hold 
at this temperature for several hours or until the dry 
gum has absorbed all the water it will hold. It does 
not go into true solution in water but will absorb about 



22 AN ICE CREAM LABORATORY GUIDE 

fifty times its own weight of the water. Strain 
through a coarse strainer and cool. It is then ready 
for immediate use. Sometimes enough is made at one 
time to last for several days, in which case it is best 
to add sufficient sugar to keep it from spoiling. 



24 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER V 

FREEZING PLAIN ICE CREAM 

Freeze ice creams after the following formulas, 
which may be reduced to suit the capacity of the 
freezer used. Eight pounds of whole condensed milk 
may be substituted for eight pounds of the cream if 
desired. Fill out the rec^ord blank on opposite page. 
No. 1. 

40 pounds* of 20% cream 
8 pounds of sugar 
4 ounces of vanilla extract 
4 ounces of gelatin if desired (See page 21) 
No. 2. 
40 pounds of 20% cream 
8 pounds of sugar 
2 ounces of vanilla extract 
4 ounces of gelatin if desired (See page 21) 
lj4 pounds cocoa dissolved in four pounds of 
boiling water with one pound of sugar. 
(Chocolate may be used.) 
Cinnamon to taste if desired. 
No. 3. 
40 pounds of 20% cream 
8 pounds of sugar 
2 ounces of vanilla extract 
2 pounds of coffee (boil, strain and use enough 

to flavor to taste) 
4 ounces of gelatin if desired (See page 21) 
No. 4. 
40 pounds of 20% cream 
8 pounds of sugar 
1 pint of creme de menth syrup 
4 ounces of gelatin if desired (See page 21) 
Color pale green. 



AN ICE CREAM LABORATORY GUIDE 2^ 

EXERCISE V REPORT 

Date Receipt Number 

CREAM : ICE CREAM : 

Age Gallons 

Acidity Weight per gallon 

Temperature 



SWELL: 



STANDARDIZATION: Gallons Per cent. 

Per cent fat in cream. 



Per cent fat in milk FREEZING: 

Standardize pounds of Freezer used 

cream testing per Pounds ice used... 

cent fat. Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



That freezing is completed 

Total time required to 

Give proportion. freeze 

X = the pounds . — 

Pounds of cream used TEMPERATURE 

Pounds of milk used Of mix entering freezer 



MIX Of brine when mix reaches 

Pounds Gallons 30° F 

Weight per gallon Of ice cream when removed 

Per cent fat it should 

test Of brine at this time 

Was gelatin used? By method 1, 2 or 3? 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened 



26 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER VI 

METHODS OF MEASURING SWELL 

Freeze one or more batches of plain ice cream as as- 
signed and measure the per cent, of swell in each of 
the following ways. Record results on the opposite 
page. 
Receipt: 

40 pounds of 20% cream 
8 pounds of sugar 
4 ounces of vanilla extract 
4 ounces of gelatin if desired (See page 21) 

1. Measure the gallons of mix used. Then 
measure in packing cans the gallons of ice cream ob- 
tained and calculate the per cent, of swell. 

2. Weigh one gallon of the mix. Weigh the first 
gallon and the last gallon of ice cream removed from 
the freezer and calculate the per cent, of swell in each 
case. 

3. Take two samples, perferably from different 
packing cans of ice cream from the same freezer, and 
determine the per cent, of swell by the method given 
in Bulletin 241 of the Wisconsin Station as fohows: 
Take a 50 cc. sample of ice cream with the sampler 
furnished you and transfer to a 300 cc. beaker, using 
exactly 200 cc. of hot water to melt it. Then transfer 
all of this to a 250 cc. Florence flask and add 1 or 2 cc. 
of ether (measured) to reduce the foam. Next add 
enough water measured from a burette to fill the flask 
to the mark. The ether and water required represent 
the swell. Calculate the per cent, in each case. 

Which method do you consider the most accurate for 
commercial use and why? For experimental use and 
why? Give special advantages of each test. 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE VI REPORT 



27 



Date Receipt Number., 



CREAM : 
Age 

Acidity 

Temperature 



ICE CREAM : 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used... 
Pounds salt used. 




TIA/[E 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 

X r= the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 

Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 

30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened: 



28 AN ICE CREAM LABORATORY GUIDE 



HARDENING ICE CREAM 

Ice cream may be of the highest quality when re- 
moved from the freezer and yet be ruined before it 
becomes hard enough to ship unless the hardening is 
properly accomplished. The two principal methods in 
use are the salt and ice method and the artificially 
cooled dry hardening room where the cans of ice cream 
are simply set in a very cold room and hardened by still 
or circulating cold air. The temperature of such a 
room should be maintained at near zero F. With 
either method the hardening process should not require 
more than twelve hours. The packing cans should 
always be cold before they are filled with ice cream, so 
as to prevent melting in the bottom. 

Directions for hardening in salt and ice. Either 
ordinary packing tubs or a large box may be used for 
this purpose. If tubs are used, simply pack well with 
salt and ice mixed in the proportion of one to eight. 
It is necessary to repack these tubs two or three times 
a day in order to keep the ice cream hard. When 
several cans of ice cream are to be hardened at a time 
a better method, more economical in labor and material, 
is to pack the empty cans up to the covers in a large 
box, using salt and ice, one to eight. The soft ice 
cream is poured into these partly packed cans and when 
full they are completely covered with the ice and salt 
mixture. With such a box it is not necessary to re- 
pack oftener than twice a day. 



30 AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER VII 

FREEZING FRUIT ICE CREAM— HARDEN- 
ING IN SALT AND ICE 

Freeze fruit ice creams after the following formula, 
using such of the flavors as are assigned. Fill out 
record blank on opposite page. 
Receipt: 

40 pounds of 20% cream 
8 pounds of sugar 

4 ounces of gelatin in 4 pounds water 
3 quarts pulped fruit 
Color, if desired. 
Flavors: Pineapple, raspberry, peach, cherry, 
strawberry. Either fresh or canned fruit may be used. 
If a perpendicular freezer is used, the fruit should 
not be added until the ice cream begins to thicken, 
which will prevent the fruit settling to the bottom of 
the freezer. 

Harden this ice cream in a salt and ice mixture. 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE VII REPORT 



31 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAM : 

Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used... 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 
X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 
Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per ■ cent fat it should 
test 



Of brine when mix reaches 

30° F 

Of ice cream when removed 



Of brine at this time- 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened : 



32 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER VIII 
NUT ICE CREAM 

Freeze nut ice creams as assigned, using the formula 
given below. Fill out the record blank on opposite 
page. 

Flavors: Walnut, fxlbert, almond and pistachio. 

It is better if all of these, except the walnuts, are 
blanched before using by scalding with boiling water 
and removing the skins. 

Prepare the nuts by running them through a meat 
chopper and add to the ice cream after it freezes 
enough to begin to thicken. 
Receipt: 

40 pounds of 20% cream 
8 pounds of sugar 

2 ounces of vanilla extract 

4 ounces of gelatin in 4 pounds water 

3 pounds of nut meats 

If pistachio nuts are used, color the ice cream a pale 
green. 



AN ICE CREAM LABORATORY GUIDE 33 

EXERCISE VIII REPORT 



Date Receipt Number. 



CREAM : 

Age :. 

Acidity 

Temperature 



ICE CREAM : 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used... 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 

X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 

Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 
30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after It is hardened: 



34 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER IX 
BISQUE ICE CREAM 

Freeze bisque ice cream after the base formula given 
below, using such of the following flavors as are as- 
signed. Fill out the record blank on opposite page. 

Flavors: Macaroons, sponge cake, grapenuts, and 
Nabisco wafers. 
Receipt: 

40 pounds of 20% cream 
8 pounds of sugar 

3 ounces of vanilla extract 

4 ounces of gelatin in 4 pounds water 

5 pounds pulverized bread product. 

Any bread product used should be dried sufficiently 
so that it may be easily crushed into fine crumbs. If 
perpendicular freezer is used, do not add the crumbs 
until the ice cream freezes enough to begin to thicken. 



AN ICE CREAM LABORATORY GUIDE 35 

EXERCISE IX REPORT 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temi5erature 



ICE CREAM : 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing. per 

cent fat. 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used- 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 
X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 

Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 

30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? _ 

Remarks : 



Comments on ice cream after it is hardened: 



AN ICE CREAM LABORATORY GUIDE 37 



EXERCISE NUMBER X 

MAKING BRICKS AND FANCY MOULDED 
ICE CREAMS 

Freeze the following plain ice creams as assigned. 
Freeze in the order given. Fill out record blank on 
the opposite page and make bricks and molds of the 
ice cream as directed below. 
Receipts: 
No. 1. 
40 pounds of 20% cream 
8 pounds of sugar 
5 ounces of gelatin in 4 pounds water 

4 ounces of vanilla extract 
No. 2. 

40 pounds of 20% cream 
8 pounds of sugar 

5 ounces of gelatin in 4 pounds water 
1 quart pulped strawberries 

4 ounces strawberry extract 
Color pink 

No. 3. 

40 pounds of 20% cream 
8 pounds of sugar 

5 ounces of gelatin in 4 pounds water 
3 ounces of vanilla extract 

1%. pounds chocolate with 4 pounds of water and 
one pound of sugar (cocoa may be used if 
desired). 
Fill the outside of a few center mold bricks with 
vanilla ice cream. Harden in a salt and ice mix- 
ture one part salt to two parts of ice. When hard 



38 AN ICE CREAM LABORATORY GUIDE 

withdraw the center mold and fill with the straw- 
berry or chocolate ice cream. Again pack in salt 
and ice to harden. 

Fill a few fancy individual molds and pack in 
the salt and ice mixture till hard. 

Each student should make a 3 layer tri-colored brick. 
First prepare the molds, attach your name and pack in 
salt and ice to become thoroughly cold. As the vanilla 
ice cream is drawn from the freezer fill each mold one 
third full and pack in the salt and ice mixture, so that 
it will be hardened by the time the strawberry ice cream 
is ready to be drawn off. Then fill another one third 
with the strawberry. Finish filling with the chocolate, 
being sure to have the brick so full of soft cream that 
no brine can enter under the lid. Care should be taken 
each time to have the bricks set level in the salt and ice. 



AN ICE CREAM LABORATORY GUIDE 39 

EXERCISE X REPORT 

Date Receipt Number 



CREAM: ICECREAM: 

Age Gallons 

Acidity Weight per gallon. 

Temperature 



SWELL: 

STANDARDIZATION: Gallons Per cent. 

Per cent fat in cream — — ___ 



Per cent fat in milk FREEZING : 

Standardize pounds of Freezer used 

cream testing per Pounds ice used... 

cent fat. Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



That freezing is completed 

^. . Total time required to 

Uive proportion. freeze 

X = the pounds 

Pounds of cream used TEMPERATURE 

Pounds of milk used Of mix entering freezer 



^^ , ^ „ Of brine when mix reaches 

Pounds Gallons 30° F 

Weight per gallon Of ice cream when'removed 

Per cent fat it should 

test Of brine at this time 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened ; 



AN ICE CREAM LABORATORY GUIDE 4I 

EXERCISE NUMBER XI 

CUSTARD ICE CREAM 

Freeze custard ice creams after the following re- 
ceipts as assigned and fill out report blank on opposite 
page. Quantities given are for hand freezers. 
Receipts: 
No. 1. 

6 quarts of milk 
3 pounds of sugar 
24 eggs 

12 tablespoonfuls of cornstarch 
6 tablespoonfuls of vanilla or to taste. 
Put the milk over the fire in a farina or double water 
boiler. Moisten the cornstarch with a little cold milk 
so that it can be added to milk without lumping. 
When the milk is hot, add the cornstarch and stir until 
it begins to thicken. Beat the eggs and sugar together 
until light and then add them to the hot milk. Cook 
a few minutes, take from fire, flavor and cool and 
freeze same as ice cream. 

Other flavors as coffee or chocolate may be made by 
substituting these flavors for the vanilla. 
No. 2. 

5 quarts milk 

1 quart 30% cream 

8 eggs 

2}4 pounds sugar % 

6 tablespoonfuls flour 

I3/2 ounces of vanilla or to taste 
Follow directions given for No. 1. 



42 AN ICE CREAM LABORATORY GUIDE 

No. 3. 

2 quarts 30% cream 
4 quarts of milk 

3 pounds of sugar 

1^ quarts Minute Tapioca 
yolks of 4 eggs 

1 teaspoonful salt 

4 teaspoonfuls lemon extract 

2 teaspoonfuls rose extract 

Cook the tapioca in two quarts of milk for 10 
minutes, then add the rest of the milk, the sugar and 
salt. Cook ten minutes longer. Remove from fire and 
add the egg yolks well beaten. Then add the extract, 
cool, and freeze. When nearly done, add the cream 
previously beaten to stiff froth and finish freezing. 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE XI REPORT 



43 



Date Receipt Number.... 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAM : 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk. 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used... 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 

X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 
Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 

30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened 



AN ICE CREAM LABORATORY GUIDE 45 

EXERCISE NUMBER XII 

PARFAIT OR FRENCH ICE CREAM 

Freeze the following receipts as assigned and fill out 
report blank on opposite page. 
Receipts: 
No. 1. 
40 pounds of 20% cream 
10 pounds of sugar 
4 ounces of vanilla extract 
8 dozen eggs well beaten 
Beat the egg yolks till smooth, add the sugar, and 
beat again till it is dissolved. Beat the whites to a stifY 
froth and stir into the yolks and sugar. Mix all with 
the cream and cook in a double boiler to a temperature 
of 180 degrees F. for 15 minutes. Cool to 40 degrees 
F., add vanilla and freeze. 
No. 2. 
40 pounds of 28% cream 
10 pounds of sugar 
4 ounces of vanilla extract 
8 dozen eggs well beaten 
2 quarts crushed strawberries 
Beat whole eggs together, add to the mix and freeze, 
or the whites may be beaten separately if desired and 
added after the mix is partly frozen. 
No. 3. 
40 pounds of 25% cream 
12 pounds of sugar 
4 ounces of vanilla extract 
4 pounds chopped walnut meats 
yolks of 8 dozen eggs 



46 AN ICE CREAM LABORATORY GUIDE 

Beat the egg yolks till smooth, add the sugar and 
beat again. Then add to the cream and cook in double 
boiler to 180 degrees F. for 15 minutes. Cool, add the 
balance of the mix and freeze. 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE XII REPORT 



47 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAM : 

Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used- 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 
X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 

Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 

30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after It is hardened: 



AN ICE CREAM LABORATORY GUIDE 49 

EXERCISE NUMBER XIII 

PUDDINGS 

Freeze the following puddings as assigned and fill 
out report blank on opposite page. 
Receipts: 

No. 1. — Nesselrode. 
32 pounds 28% cream 
10 dozen eggs 
10 pounds of sugar 
6 ounces vanilla 

4 pounds chopped walnut meats 
3 pounds chopped candied cherries 

3 pounds chopped candied fruits 

4 pounds chopped raisins 

Cook the ^gg yolks with the cream. Beat the whites 
and add when partly frozen. 
No. 2 — English Plum. 
32 pounds 25% cream 
8 dozen eggs 
12 pounds sugar 
3 pounds cocoa or chocolate 

5 pounds assorted fruits that do not pulp 

2 pounds seeded raisins 

3 pounds dates 

4 pounds walnut meats 

4 tablespoonfuls ground cinnamon 
1 tablespoonful ginger 
1 tablespoonful ground cloves 
Use the eggs as directed under receipt number one. 
Chop the fruits and nuts fine. 



50 AN ICE CREAM LABORATORY GUIDE 

No. 3. — Fruit Pudding 
32 pounds 10% cream 

8 pounds whole condensed milk 

8 pounds of sugar 

5 ounces of gelatin dissolved in part of cream 

2 pounds chopped cherries 

2 pounds chopped raisins 

2 pounds chopped nuts 

1^ quarts sherry wine 
Soak the fruit over night in the sherry wine. 



AN ICE CREAM LABORATORY GUIDE 5 1 

EXERCISE XIII REPORT 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAM : 

Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used- 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 
X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 
Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 

30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after It is hardened ; 



52 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XIV 

ICES 

Freeze the following water ices as assigned and fill 
out record blank on opposite page. 
Receipts: 
No. 1. 
48 pounds of water 
20 pounds of sugar 
6 pounds of lemon juice 
No. 2. 

48 pounds of water 
20 pounds of sugar 
2 pounds of lemon juice 
4 quarts pineapple juice 
No. 3. 

48 pounds of water 
20 pounds of sugar 
2 pounds of lemon juice 
4 quarts finely pulped strawberries 
No. 4. Same as number two, except freeze very 
rapidly with little agitation. This is often 
called a granite. 



AN ICE CREAM LABORATORY GUIDE 53 

EXERCISE XIV REPORT 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAM : 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL : 
Gallons Per cent. 



FREEZING : 

Freezer used 

Pounds ice used- 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 
X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 

Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 
30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks ; 



Comments on ice cream after it is hardened 



54 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XV 

WATER SHERBETS 

Freeze the following sherbets as assigned and fill out 
record blank on opposite page. 
Receipts: 
No. 1. 
48 pounds water 
16 pounds sugar 
1 pound lemon juice 

4 quarts grated pineapple (or pineapple juice) 
6 ounces of gelatin in 4 pounds of water, if de- 
sired 
24 Qgg whites beaten stiff and added when mix- 
ture is partly frozen 

No. 2. Same as number one except replace the pine- 
apple with grape juice. 

No. 3. Use same mix as number one except re- 
place the pineapple with orange juice. 
Boil the water and sugar to a clear syrup, 
then strain and cool before freezing. 



AN ICE CREAM LABORATORY GUIDE 55 

EXERCISE XV REPORT 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAM : 

Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used... 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F. 

Required to reach 30° F. 



Give proportion. 
X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE ~ 

Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 
30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened : 



56 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XVI 

MILK SHERBETS 

Freeze milk sherbets after the following base for- 
mula, using such of the flavorings as are assigne !. 
Fill out the record blank on the opposite page. 

Flavors : Orange, grape, cherry, pineapple, and 
strawberry. If lemon is desired, use only two quarts 
of lemon juice with a quart of orange juice. 
Receipt: 

48 pounds of milk 
16 pounds of sugar 
5 ounces of gelatin in 2 quarts water 
1 pound lemon juice 
4 quarts fruit flavoring 

12 Qgg whites beaten stiff and added after mix- 
ture is partly frozen. 



AN ICE CREAM LABORATORY GUIDE Cy 

EXERCISE XVI REPORT 

P^^^ Receipt Nu mber 

CREAM: ICECREAM: 
Age Gallons 

^^ature-z:::::::::; ^^'^'^^ p- ^'^- 



SWELL : 



STANDARDIZATION: Gallons Percent 

Per cent fat in cream — — 

Per cent fat in milk FREEZING- 

Standardize pounds of Freezer used 

cream testing per Pounds ice used 

c^"t fat. Pounds salt used 




TIME 
Of starting freezer 

That mix reaches 30° F.."" 
Required to reach 30° R 



That freezing is completed 

Give proportion. "^"freeze'™" "^^'^ "^ 

X =3 the pounds -^ 

Pounds of cream used TEMPERATURE 

Pounds of milk used Of mix entering freezer 

^Pounds Gallons ^\^o%' ^^^" "^^" ^^^^^^^ 

'^s'^'Lir g^^^^-shouid ^^.^- :::^ 

^^^^- Of brine at this time 



Was gelatin used? By method 1, 2 or 3? 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened : 



58 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XVII 

PUNCHES AND LACTO 

Freeze the following formulas as assigned and fill 
out the record blank on opposite page: 
Punches: 
No. 1. 

48 pounds water 
20 pounds sugar 
1 pound lemon juice 
1 quart brandy and rum mixed 
No. 2. 

48 pounds water 
20 pounds sugar 
1 pound lemon juice 

1 quart orange juice 

2 quarts wine 

4 ounces gelatin in part of the water 
No. 3. 
48 pounds water 
20 pounds sugar 

1 quart lemon juice 

1 quart raspberry juice 

1 quart grape juice 

cloves, cinnamon, allspice and nutmeg to taste. 
Lacto (From Iowa Station Bulletin 140) 

48 pounds good starter just nicely coagulated 

18 pounds sugar 

24 eggs, whites and yolks beaten separately 

2 quarts of grape juice 
1^ quarts lemon juice 

Mix in the order given in the formula. Other 
flavors may be substituted for the grape juice. 



AN ICE CREAM LABORATORY GUIDE $9 

EXERCISE XVII REPORT 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAAi: 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cieam 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 

-<- 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used... 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 
X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 
Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 
30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened : 



6o AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XVIII 

MOUSSE 

Prepare and freeze mousse after the following 
formulas as assigned. 
No. 1. — For five gallons 
20 pounds aged sweet cream, at least 40% fat 

5 pounds sugar 

6 ounces of gelatin 
juice of three lemons 

3 quarts strained strawberry juice 

Dissolve the sugar in the fruit juice, then stir in the 
gelatin dissolved in a very little water. Chill this 
mixture but not enough to form a jelly. Whip the cold 
cream till stiff and then fold in the gelatin-sugar-fruit 
mixture. 

Pack into molds or cans and harden in a salt and ice 
mixture one to two. Other flavors may be substituted. 

No. 2. — For five gallons 

20 pounds of aged sweet cream, 35% fat 

4 pounds of sugar 

5 ounces of gelatin 
2^ ounces of vanilla 

Dissolve the gelatin and stir into the cream. Whip 
till stiff, then fold in the sugar and vanilla and pack in 
cans, hardening in salt and ice mixed one to two. 

Report results on opposite page. 



AN ICE CREAM LABORATORY GUIDE ' 6l 

EXERCISE XVIII REPORT 



(i2 AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER XIX 

STANDARDIZE MIX TO A GIVEN PERCENT- 
AGE OF FAT 

The following materials will be furnished : cream, 
milk, sugar, chocolate, fruit, vanilla and gelatin. From 
them make up a receipt and freeze a batch of ice cream 
to contain a given per cent, of fat as assigned. 

Test the frozen ice cream for fat and report the re- 
sult to the instructor at time of testing. 

Include your receipt and all calculations and tests 
on opposite page. 

Mark plainly each can of ice cream with the receipt 
number, your name, and the date. 

No. 1. Vanilla ice cream to test 14% fat. 

No. 2. Vanilla ice cream to test 12% fat. 

No. 3. Vanilla ice cream to test 9^% fat. 

No. 4. Fruit ice cream to test 11% fat. 

No. 5, Chocolate ice cream to test 12% fat. 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE XIX REPORT 



63 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAM: 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL: 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used... 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 

21 = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 

Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 



Of brine when mix reaches 

30° F 

Of ice cream when removed 



test. 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened : 



64 AN ICE CREAM LABORATORY GUIDE 



SCORE CARD FOR ICE CREAM 

The comparison of ice creams is accomplished best 
by reducing their quahty to a numerical basis. This 
is done by use of a score card. Two score cards are 
suggested as follows : 

Modification of the 
Cornell Score Card Wisconsin Score Card 

Flavor 45 Flavor 40 

Body and texture 35 Body and texture 25 

Richness 10 Bacterial count 15 

Appearance 5 Richness 10 

Package 5 Appearance 5 

Package 5 

100 100 

It may be more advantageous to use the Cornell score 
card in the Laboratory because immediate results can 
be obtained, while with the modified Wisconsin score 
card bacterial counts must be made of the ice cream, so 
that it would be two to three days before the final score 
of the ice cream could be obtained. 

Discussion of Qualities of Ice Cream 

Flavor. The ice cream should have a pronounced 
flavor which will blend with the flavor of the cream to 
give a clean, desirable typical flavor. 

Body and Texture. The body should be firm and 
mellow. It should not be tough or rubbery neither 
soft or mushy. The texture should be smooth and 
velvety and entirely free from graininess and lump- 
iness. 

Richness. If the ice cream meets the legal require- 
ments, it should be given a perfect score. If it falls 
below the legal requirement, it should be scored zero. 



AN ICE CREAM LABORATORY GUIDE 65 

Appearance. The ice cream should have an at- 
tractive appearance and be of the characteristic uniform 
color. 

Package. The package should be neat and clean 
and, if for long shipment, some provision should be 
made to protect the ice on top of the packing tub. 

Bacterial count. An ice cream which has a count of 
20,000 should be considered perfect. For each in- 
crease of 20,000 above this one point should be de- 
ducted from the score. 

Application of score card. When judging samples 
of ice cream, it is best to try some of them to obtain 
some idea of the qualities of the samples to be scored. 
This is necessary so that the score will not run above 
100 and to set a standard. Then with a definite stand- 
ard in mind, the samples may be carefully scored. The 
cuts in score should be made in proportion to the 
quality of the ice cream and the definite standard in 
mind. 



66 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XX 
JUDGING PLAIN ICE CREAM 

Score and criticize the samples of plain ice cream 
recording the scores on the opposite page. (For score 
card see page 64.) 

One sample will first be scored by the instructor as 
an example and guide to the severeness of the cut for 
different defects. After the students have finished, he 
will score the remaining samples with them. 

Three of the samples are ice cream made in the 
college laboratory. The others are purchased and 
represent well known commercial ice creams. 

After scoring on all other points make a fat test of 
each sample. (See page 14.) 



AN ICE CREAM LABORATORY GUIDE 



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68 AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER XXI 

THE EFFECT OF FAT CONTENT ON ICE 
CREAM 

Part I. Freeze ice creams after the following for- 
mulas as assigned.. Each has a different percentage of 
fat. Fill out the record blank on opposite page and 
mark plainly each can of ice cream with the receipt 
number, your name and the date. 
Receipts: 
No. 1. 

40 pounds of 10% cream 
8 pounds of sugar 
4 ounces of vanilla extract 
4 ounces gelatin in 4 pounds water. 
No. 2. Same as No. 1 except use 15% cream. 
No. 3. Same as No. 1 except use 20% cream. 
No. 4. Same as No. 1 except use 30% cream. 
No. 5. Same as No. 1 except use 40% cream. 
Part II. After hardening or next laboratory period 
score and criticize the ice cream made in Part I. Fill 
in the score blank on page 90. 



AN ICE CREAM LABORATORY GUIDE 69 

EXERCISE XXI REPORT 
PARTI 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAA! : 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 

-< 



SWELL: 

Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used... 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 
X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 
Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 

30° F 

Of ice cream when removed 



Of brine at this time- 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened: 



70 AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER XXII 

THE EFFECT OF DIFFERENT BINDERS ON 
ICE CREAM 

Part I. Freeze the following mixes as assigned. 
Fill out record blank on opposite page, and mark each 
can of ice cream plainly with receipt number, your 
name and date. 
Receipts: 
No. 1. 

40 pounds 16% cream 
8 pounds sugar 
4 ounces vanilla 

2 quarts of gum stock (See page 21) 
No. 2. Same as No. 1 except use 4 ounces of gela- 
tin in 33/2 pounds of water as a binder. 
Nos. 3, 4, 5. In these use different ice cream pow- 
ders as binders, following the directions 
given with each powder as to quantities to 
use and method of mixing. Use a formula 
which will give the same per cent, of fat 
and soHds not fat as No. 1. 
Part II. After hardening or at the next laboratory- 
period score and criticize the ice creams made in Part 
I. Fill out the score blank on page 91. 



AN ICE CREAM LABORATORY GUIDE 7 1 

EXERCISE XXII REPORT 

PART I 

Date Receipt Number 

CREAM : ICE CREAM : 

Age Gallons 

Acidity Weight per gallon 

Temperature 



SWELL : 

STANDARDIZATION: Gallons Per cent. 

Per cent fat in cream 



Per cent fat in milk FREEZING: 

Standardize pounds of Freezer used 

cream testing per Pounds ice used- 
cent fat. Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



That freezing is completed 

Total time required to 

Give proportion. freeze 

X = the pounds 

Pounds of cream used TEMPERATURE 

Pounds of milk used Of mix entering freezer 



MIX Of brine when mix reaches 

Pounds Gallons 30° F 

Weight per gallon Of ice cream when removed 

Per cent fat it should 

test Of brine at this time 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened : 



"J^ AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER XXIII 

THE EFFECT OF VARYING PERCENTAGES 
OF MILK SOLIDS NOT FAT ON 
ICE CREAM 

Part I. Freeze the following mixes as assigned. 
Fill out record blank on opposite page. Mark each 
can of ice cream you freeze with receipt number, your 
name and date. Calculate and record the approxi- 
mate per cent of fat and of milk solids not fat in each 
mix. 

Receipts No. i 

Cream 40 lbs. 

15% 
Whole Condensed 

Milk 

Sugar 8 lbs. 

Vanilla 4oz. 

Gelatin 4 oz. 

Water 4 lbs. 

Per cent Fat 

Fer cent Milk S. N. F. 

Part II. After hardening or at next laboratory 
period score the ice creams as made above. Fill out 
the score blank on page 92. 



No. 2 


No. 3 


No. 4 


35 lbs. 


30 lbs. 


25 lbs. 


15/2% 


162/3% 


18% 


5 lbs. 


10 lbs. 


15 lbs. 


8 lbs. 


8 lbs. 


8 lbs. 


4oz. 


4 oz. 


4 oz. 


4oz. 


4oz. 


4 oz. 


4 lbs. 


4 lbs. 


4 lbs. 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE XXIII REPORT 
PARTI 



73 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAM : 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL: 
Gallons.. 



Per cent. 



FREEZING: 

Freezer used 

Pounds ice used... 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 
X = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 
Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 
30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it Is hardened : 



74 AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER XXIV 

FREEZE ICE CREAM FROM RAW, PASTEUR- 
IZED, EMULSIFIED AND HOMO- 
GENIZED CREAM 

Note effect on swell and quality of ice cream. 
In order to have the ice cream in condition to make 
easy comparison, it should all be made after the same 
receipt. 

40 pounds 20% cream 
8 pounds sugar 
4 ounces vanilla extract 
4 ounces gelatin in 4 pounds water 
With sufficient fresh cream to make four batches of 
ice cream, divide the cream into four equal parts. 
I. Freeze one part directly. 
II. Pasteurize one part and freeze. 

III. Emulsify one part and freeze. 

IV. Homogenize one part and freeze. 

If desired all may be aged before freezing. 
Fill out record blank on opposite page. 



AN ICE CREAM LABORATORY GUIDE 75 

EXERCISE XXIV REPORT 



Batch Number 


1 


2 


3 


4 








Pounds of Mix 














Gallons of Mix 














Temperature of Mix 














Time of Starting Freezer 














Time of Stopping Freezer 














Temperature of Ice Cream 














Gallons of Ice Cream 














Gallons of Swell 










Per Cent of Swell 















Comments : 



76 AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER XXV 

THE EFFECT OF AGING CREAM ON THE 
VISCOSITY AND SWELL 

Twenty per cent, cream of nearly uniform quality 
will be furnished you, of the following ages from the 
separator : three to four hours, one day, two days, three 
days, and five days. Freeze a batch of each as as- 
signed, using the following formula, and pay special 
attention to the swell obtained. 

Also test each cream for viscosity by dropping from 
a pipette on an inclined glass, taking care to have 
the glass and pipette of even temperature for each 
trial. 

Fill out blank report on opposite page. 
Receipt: 

40 pounds 20% cream 
8 pounds sugar 
4 ounces vanilla extract 
4 ounces gelatin in 4 pounds water. 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE XXV REPORT 



17 



Date Receipt Number. 



CREAM : 

Age 

Acidity 

Temperature 



ICE CREAM: 
Gallons 

Weight per gallon. 



STANDARDIZATION : 

Per cent fat in cream 

Per cent fat in milk 

Standardize pounds of 

cream testing per 

cent fat. 



SWELL : 
Gallons Per cent. 



FREEZING: 

Freezer used 

Pounds ice used- 
Pounds salt used. 




TIME 

Of starting freezer 

That mix reaches 30° F 

Required to reach 30° F. 



Give proportion. 

21 = the pounds 

Pounds of cream used. 
Pounds of milk used 



That freezing is completed 

Total time required to 
freeze 

TEMPERATURE 

Of mix entering freezer 



MIX 

Pounds Gallons 

Weight per gallon 

Per cent fat it should 
test 



Of brine when mix reaches 
30° F 

Of ice cream when removed 



Of brine at this time. 



Was gelatin used? By method 1, 2 or 3?. 

In milk or water? 

Remarks : 



Comments on ice cream after it is hardened : 



yS AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER XXVI 

THE EFFECT OF THE TEMPERATURE OF 

THE MIX AS IT ENTERS THE FREEZER 

ON THE SWELL 

Make enough mix for four 10 gallon batches of ice 
cream, using the following formula: 
40 pounds of 20% cream 
8 pounds of sugar 
4 ounces of vanilla extract 
4 ounces of gelatin in 4 pounds water. 
Freeze the first batch as a preliminary one. Have 
the second at a temperature of 40 degrees F., when it 
enters the freezer, the third at 50 degrees F., and the 
fourth at 60 degrees F. Warm to these temperatures 
before placing mix in freezer. Note swell obtained. 
Explain. 

Fill out record blank on opposite page. 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE XXVI REPORT 



79 



Batch Number 


1 


2 


3 


4 






Pounds of Mix 










Gallons of Mix 














Temperature of Mix 














Time of Starting Freezer 










Time of Stopping Freezer 










Temperature of Ice Cream 










Gallons of Ice Cream 










Gallons of Swell 










Per Cent of Swell 











Comments 



So AN ICE CREAM LABORATORY GUIDE 



EXERCISE NUMBER XXVII 

EFFECT OF THE TIME OF FREEZING ON 
THE SWELL AND QUALITY OF 
ICE CREAM 

Make enough mix for four 10 gallon batches of ice 
cream, using the following formula: 
40 pounds of 20% cream 
8 pounds of sugar 
4 ounces of vanilla extract 
4 ounces of gelatin in 4 pounds water 
Freeze the first batch as a preliminary one. Regu- 
late either the temperature or quantity of brine so that 
the second batch will freeze in four minutes, the third 
in fifteen minutes, and the fourth in thirty minutes. 
Note particularly the effect on the swell and quality. 
Fill out the record blank on opposite page. 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE XXVII REPORT 



8i 



Batch Number 


1 


2 


3 


4 






Pounds of Mix 














Gallons of Mix 














Temperature of Mix 














Time of Startmg Freezer 














Time of Stopping Freezer 














Temperature of Ice Cream 














Gallons of Ice Cream 










Gallons of Swell 














Per Cent of Swell 















Comments : 



82 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XXVIII 
BACTERIAL COUNTS OF ICE CREAM 

This exercise is to be performed once during the 
course by each student as assigned. 

Sterile glassware and media will be furnished you. 
Weigh or measure the samples for dilution as in- 
structed. 

Take samples as indicated below in sterile bottles 
and plate on plain lactose agar. Incubate at 37 degrees 
C, for 48 hours. 

Sample of cream. Dilutions 1/10,000 and 1/100,000. 

Sample of gelatin. Dilutions 1/10 and 1/100. 

Sample of vanilla. Dilutions 1/10. 

Sample of sugar. Dilutions 1/10. 

Sample of mix. Dilutions 1/10,000 and 1/100,000. 

Sample of ice cream from freezer. Dilutions 
1/10,000 and 1/100,000. 

Sample of ice cream after it has remained in the 
hardening room one week. Make dilutions of 1/10,000 
and 1/100,000. 

Report results on the blank page opposite. 



AN ICE CREAM LABORATORY GUIDE 83 

EXERCISE XXVIII REPORT 



84 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XXIX 
TESTING SAMPLES OF GELATIN 

Weigh 5 gram samples of gelatin into 100 cc. of cold 
water in beakers or jelly glasses. Allow it to soak over 
night. Then heat slowly, with stirring, to 80 de- 
grees C. 

Subject to the following tests and make report on 
opposite blank page. 

L Note the odor. 

2. Determine the time required for 50 cc. to run 
from a pipette. 

3. Determine the time required for the sample to 
gelatinize. 

4. Turn the jelly out on to a plate and determine the 
relative resistance of the different samples to 
pressure by the finger. 

Two or more students should be assigned to this 
exercise at a time, each having a different sample of 
gelatin. They should perform the tests together. 



AN ICE CREAM LABORATORY GUIDE 85 

EXERCISE XXIX REPORT 



86 AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XXX 

TRIP TO COMMERCIAL PLANTS 

Visit at least one large commercial plant some time 
during the term and report on the following points. 
Points to be observed in an ice cream plant. 
L Method of securing the raw product. 

2. Is cream pasteurized? 

3. If possible, amounts and materials used in mix. 

4. Is condensed milk used ? 

5. What stabilizer is used? 

6. Time of aging cream or mix. 

7. Kinds of freezer and ice machine. 

8. Temperature of brine to freeze. 

9. Composition of ice cream. 

10. Sketch of arrangement of plant. 

n. Power used for delivering. 

12. Method of checking up drivers. 

13. Any other points of interest. 



AN ICE CREAM LABORATORY GUIDE 8/ 

EXERCISE XXX REPORT 



OO AN ICE CREAM LABORATORY GUIDE 

EXERCISE NUMBER XXXI 
STUDENTS' RECEIPTS 

Each student should hand in one receipt for ice 
cream. This receipt should be one which has been 
previously tried, preferably at home. 

During- the term these receipts will be made. 

Note the quality of the ice cream. 

Is the ice cream a good commercial ice cream? 

Could it be made on a commercial basis profitably ? 



AN ICE CREAM LABORATORY GUIDE 

EXERCISE XXXI REPORT 



90 



AN ICE CREAM LABORATORY GUIDE 



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